In State v. Miguel, 2 S.W.3d 249, 251 (Tex. 1999) the department of transportation had placed barrels in front of a section of an elevated exit ramp's missing railing to serve as a temporary warning device. Id. at 250. The driver's van struck the barrels, hurdled over an eighteen inch concrete parapet wall, and fell about sixty feet to the ground. Id. However, the court alluded to the fine distinction to be drawn between discretionary and nondiscretionary functions in this type of case: The State contends that the decision to warn of the missing guardrail with barrels and signs is discretionary. We agree. Respondent's allegations are based on the State's decision to use barrels, not upon any claim that the State negligently placed the barrels. Id. at 251. The court explained that the maintenance crew was merely carrying out the policy of the State because the barrel and sign warning system chosen by the crew complied with the department of transportation's Manual on Uniform Traffic Control Devices. Id. Thus, the court held that the decision to warn rather than repair was discretionary, and the decision to use barrels and signs, as opposed to another warning device, was discretionary. Id. In contrast, when a governmental unit fails to maintain public works, such as a storm drainage system, or street and storm sewers, those activities are not discretionary functions. See City of Fort Worth v. Gay, 977 S.W.2d 814, 817 (Tex. App.--Fort Worth 1998, no pet.) (holding city not immune from liability where claims were based on the City's failure to maintain, clean, and inspect an area of the street).